Drinking tumbler



FIG. 1 is a plan view illustration of the drinking tumbler of the ornamental design;

FIG. 2 is a front elevational view of the drinking tumbler of the ornamental design, the rear and side elevational views thereof being identical with the front elevational view;

FIG. 3 is a bottom view of the drinking tumbler of the ornamental design; and,

FIG. 4 is a vertical sectional view of the ornamental design, showing the wall structure and inside surface thereof. 

The ornamental design for a drinking tumbler, as shown and described. 